﻿<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>canvas画布作为纹理贴图</title>
    <script src="../../js/three.js"></script>
    <script src="../../js/controls/OrbitControls.js"></script>
    <style type="text/css">
        body {
            margin: 0;
            overflow: hidden;
        }
    </style>
</head>

<body>
    <script type="text/javascript">
        /**
         * 创建场景对象Scene
         */
        var scene = new THREE.Scene()
        var geometry = new THREE.PlaneGeometry(128, 32); //矩形平面
        /**
         * 创建一个canvas对象，并绘制一些轮廓
         */
        var canvas = document.createElement('canvas')
        canvas.width = 512
        canvas.height = 128
        var c = canvas.getContext('2d')
        // 矩形区域填充背景
        c.fillStyle = "#ff00ff";
        c.fillRect(0, 0, 512, 128);
        c.beginPath();
        // 文字
        c.beginPath();
        c.translate(256, 64);
        c.fillStyle = "#000000"; //文本填充颜色
        c.font = "bold 48px 宋体"; //字体样式设置
        c.textBaseline = "middle"; //文本与fillText定义的纵坐标
        c.textAlign = "center"; //文本居中(以fillText定义的横坐标)
        c.fillText("乐心瑶", 0, 0);

        // canvas画布对象作为CanvasTexture的参数重建一个纹理对象
        // canvas画布可以理解为一张图片
        /**
         * CanvasTexture参数：canvas, mapping, wrapS, wrapT, magFilter, minFilter, format, type, anisotropy
         * 
         */
        var texture = new THREE.CanvasTexture(canvas);
        // var texture = new THREE.Texture(canvas);
        // texture.needsUpdate = true;
        //打印纹理对象的image属性
        // console.log(texture.image);
        var material = new THREE.MeshPhongMaterial({
            map: texture, // 设置纹理贴图
        }); //材质对象Material
        var mesh = new THREE.Mesh(geometry, material); //网格模型对象Mesh
        scene.add(mesh); //网格模型添加到场景中
        /**
         * 光源设置
         */
        //点光源
        var point = new THREE.PointLight(0xffffff);
        point.position.set(400, 200, 300); //点光源位置
        scene.add(point); //点光源添加到场景中
        //环境光
        var ambient = new THREE.AmbientLight(0xaaaaaa);
        scene.add(ambient);
        /**
         * 相机设置
         */
        var width = window.innerWidth; //窗口宽度
        var height = window.innerHeight; //窗口高度
        var k = width / height; //窗口宽高比
        var s = 150; //三维场景显示范围控制系数，系数越大，显示的范围越大
        //创建相机对象
        var camera = new THREE.OrthographicCamera(-s * k, s * k, s, -s, 1, 1000);
        camera.position.set(200, 300, 200); //设置相机位置
        camera.lookAt(scene.position); //设置相机方向(指向的场景对象)
        /**
         * 创建渲染器对象
         */
        var renderer = new THREE.WebGLRenderer();
        renderer.setSize(width, height); //设置渲染区域尺寸
        renderer.setClearColor(0xb9d3ff, 1); //设置背景颜色
        document.body.appendChild(renderer.domElement); //body元素中插入canvas对象

        // 渲染函数
        function render() {
            renderer.render(scene, camera); //执行渲染操作
            requestAnimationFrame(render);
        }
        render();
        //创建控件对象  相机对象camera作为参数   控件可以监听鼠标的变化，改变相机对象的属性
        var controls = new THREE.OrbitControls(camera, renderer.domElement);
        //监听鼠标事件，触发渲染函数，更新canvas画布渲染效果
        controls.addEventListener('change', render);
    </script>
</body>

</html>